Slide projector apparatus



y 1945. B. STECHBART ETAL 2,375,706

I SLIDE PROJECTOR APPARATUS Filed June 17, 1942 6 Sheets-Shet 1 4 I INVENTEIRSZ W 1945. B. STECHBART ET AL 2,375,706

SLIDE-.PROJECTOR APPARATUS 'Filed June '17, 1942 '6 Sheets-Shy eet 2 i if INVENTDRS EIRUNU EITEEHBART EDWARD E. ETRALIEIE:

1 AT TY.

y ,v B. STECHBART ETAL SLIDE PROJECTOR APPARATUS Filed Jun e 17., 1942 e Sheets-Sheet s INVENTEIRE BRuNnj ETEE-HBAHT EDWARD E. ETRALIEE WM V I ATM May a, 1945. I

a. STECHBART ET AL SLIDE PROJECTOR APPARATUs Filed June 17, 1942 e Sheets-Sheet 4 ER NU ETEEHB RT EDWARD E. ETRALISE BYM May 8,

B. STECHBART ET AL SLIDE PROJECTOR APPARATUS Filed Jufie 17, 1942 6 Sheets-sheet 5 V/QOX [415 Ill EDWARD E.

F INVENTDREJ' EIRLIN EITEEHBART ETRALIEE y 4 B. STECHBART ETAL 2,375,706

' SLIDE PROJECTOR APPARA'IUS Filed Jun 17, 1942 6 ShQe ts -Sheet 6 INVENTEIRS BRUNEI 'ETEEIjBART EDWARD E. STRAUSS 4 ATTY 4 'cally through a projector Fig.1;

Patented May 8, 1945 2,375,706 SLIDE PROJECTOR APPARATUS Bruno Stechbart.

Park Ridge, and Edward E.

Strauss, Wilmette, lli., asslgnors to The Bell & Howell: Company, Chicago, 111., a corporation of n" p Application June 173' 1942, Serial No. 447,316

, 12 Claims. Our invention relates more particularly to proctor apparatus of the character wherein graphic subject matter photographically produced as upon slides is projected upon a viewing screen by means of a light beam.

The general object of this invention is the provision of a novel andefl'ective projector or viewing apparatus automatically operable to run through a series of slides in a holder or carrier therefor by transferring them from a transfer station at which they are successively disposed by such holder, into a projecting or viewing section of the apparatus, and, subsequent to individual projection or viewing thereof for a desired or predetermined period, returning the same to the like transfer and return of holder preparatory to succeeding slides as they are disposed at the transfer station, such object further including the provision of a driving motor for the apparatus together with timing means controlling th length of time the apparatus allows the slides to remain in the projecting or viewing section, and also a plurality of slide holders or carriers from which the slides are alternately transferred and returned as aforesaid.

The invention will be better understood by reference to the accompanying drawings, inwhich- Fig. 1 is a transverse sectional view taken vertimachine constructed according to the principles of the invention, the view being taken upon the line l-l in Fig. 4;

Fig. 2 is a view similar to Fig. 1 but showing the parts of the machine in a diiferent position of operation Fig. 3 is a perspective view of a cam plate for operating a shutter of the machine; Fig. 4 is a vertical sectional view taken through the machine upon a plane at right angles to that upon which Figs. 1 and 2 are taken, and substantially as indicated at the line 4l in Fig. 5 is a horizontal fragmentary sectional vilegw taken substantially n w. aview taken imilarly tcrinstct tion, a slide picker device for transferring slides to upon the line 8-4 in p .4 showing several of th parts in a diiierent operatsndofwhiehthelei'tmos'tllidelsia so that thethe projecting section of the machine :and of,

which the rightmost slide is at" a transfer station and still contained within its respective slide holder; Fig. 10 is a perspective view showing the details of a slide, together with a transparency contained therein, of atom adapted to be handled automatically by the machine;

Fig. 11 is a diagrammatic view illustrating driving and timing motors for the machine together with an electric control circuit therefor;-

Fig. 12 is a sectional view of the timing motor and speed reducing gearing associated therewith;

Figs. l3 and 14 are plan views of switches shown diagrammatically in Fig. 11 and cam means associated therewith for operating the same in ac cordance with the speed of the timing motor, the views showing the cam and switches in diflerent stages of operation;

Figs. 15 and 16 are plan views of switches, also shown diagrammatically in Fig. 11, operable cooperably with the switches in Figs. 13 and 14 for controlling the energization of the driving motor control circuit, the switches being shown in dif- .ferent operating positions in the two figures Fig. 17 is a diagrammatic view of a manually controlled circuit portion substitutable for the cam-controlled circuit portions in Fig. 11, to render the apparatus periodically operable according to manual initiation instead of automatically operable at predetermined intervals.

Pnrtnrmur Psssrrcrrvr A 'ge'rieral knowledge of the machine and its operation may be gained from an examination of Figs. 1, 2 and 4. In these figures the machine can be seen to comprise a housing H having .slide holder drums D disposed on opposite sides "thereof and in coaxial relation. The drums D are rotatable and carry about their peripheries a plurality of slides 8 which are slidable axially from the drums into a projecting section P5 of 1 the housing H. A feed or slide picker device PD is reciprocated back and forth between the lower portions of the drums D between transfer stations T8 for alternately coupling with and transferring slides, one at a time, from the drum into the project section. P8 of the machine. As a slide is transferred from one 01 the sta tions TS into the projecting section PS, another slidewhich is then stationed inthe projecting v section is'returned to its respective drum D. Durtransfer operation a shutter is placed in registry with the machine proieeting' section subject on the slides will not be projected onto the viewing screen (not shown) while the slides are being moved. Subsequent to the disposal of the new slide into the projecting section of the picker device said succeeding slide will be trans ferred into the projecting section PS concurrently with return of the projected slide back to its respective slide holder drum. Thus each time the picker device moves from one side of the machine to the other a slide that has been projected will be returned to its respective drum and a new slide will be carried into the projecting section. v

A driving motor Dlvi supplies the driving force for the slide picker PD, the drum rotating means, the shutter and drum piloting means for holding the drums against rotation until slides withdrawn therefrom are returned, all later to be described in detail. This motor is operated intermittently, having a rest periodvwhen the shutter is in open position permitting the a slide subject upon the viewing screen;- and a constantly running timing motor TM, Figs. 1?. and 12, functions to determine the idle period of the driving motor and hence the period the slide in the projecting section PS is allowed to be projected upon the viewing screen.

FRAME AND Housmc Srnncrunn The housing H in addition to enclosing many of the moving parts of the machine also serves as a frame for the mounting thereof and about and within which the movable parts of the machine are assembled. Said housing which may be made of any selected number of parts suitably fabricated. together includes a top wall 20, a back wall 2!, a. front wall 22, side walls 23 and 24 and a bottom wall 25. From opposite sides of the bottom wall 25 there depend supporting legs 26 and 21 which may be integral with their respectively associated side walls 23 and 24 and a part of the bottom wall 25. In the present embodiment the various walls of the housing H areformed oi cast metal and any number of reinforcing ribs as shown at 28 and 25in Fig. 4 7 may be cast into the wall structure at strategic points. Threaded holes 30 and 3! are formed coaxially in the housing legs 26 and 21 for the reception of supporting means (not shown) upon which the housing may be pivotally adjusted for throwing the projector beam in the desired-100a tion with respect to-a viewin screen.

Moron AND PRIMARY Dsrvr: Snu'rmc pinion 34 formed integrally with the drive shaft drives a worm gear 35 upon a cross shaft 88 .in Figs. 5 and 6 to be 38' at oppo te of v 32 meshes with and mounted non-rotatlvely which 'is plainly shown journalled in bearings 31 and has its back end journalled in' projection of lever 52 pivoted upon a THE SLIDE CARRIER Dmms rocall'y disposed within a spring chamber directed diametrically of its associated spindle ti and a helical spring 55 also within such chamber for urging the latch member outwardly. A pin 58 extending across a slot 5 extending axially of the spindle Bl communicatively with the associated spring chamber 60, has a finger actuating outer end portion 56 and an inner end projection dd oi which the latter is adapted to force the latch member 48 inwardly against the force of the spring Bi when the outer end portion '55 is engaged by the finger tip of an operator forpivoting such lever clockwise as viewed in Fig. 4.. when this is done the latch member 5.9 will be cleared by the associated hub 6 to permit withdrawal of the drum D from the spindle. When a drum D is mounted upon a spindle Hi there is no necessity for manipulating the lever 55 since the inner end of the drum hub id will coact with a camming suriace 51 upon the latch for pressing the latter inwardly and thus allowing the drum to he slid onto the spindle $17. After the drum has been slid home the spring 5! will project the latch member outwardly into the position shown in Fi 4 for holding the drum in place.

' The drums D are identical. Each has a cylindrical part 56 spaced radially from its hub 48 by a disk portion 59 that is reinforced by a plurality of webs 6B. A second cylindrical portion is in the form of a cylindrical flange 6! arranged concentrically with the cylindrical portion 58 and connected therewith through an annulus 62. A plurality of axial undercut T -slots 68 are formed in the outer periphery of the cylindrical part 58 and a like numberof axial slots 6d are formed upon the inner periphery of the cylindrical flange 68. The slots 6% are respectivelypaired with the slots 63 and are in respective radial alignment its ends and" respectively supported upon the ,1

housing side walls 24 and 23. A worm pinion 39 on an intermediate section of the shaft '30 circumferentially of with those slots 63 with which they are paired. Each pair of slots 69 and 64 is adapted to hold a slide S in a manner that such slide can be slid axially inwardly with respect to the drum and completely free thereof for placement in the projecting section of the machine. 4/

In addition-to the slots 63 and 6] upon the drums D there is a third series of slots ornotches 65 formed in the outer periphery of a flange 86 arranged coaxialiy with the drums and projecting inwardly from their disk portions 59.

These notches 65 are equal innumber' to the grooves 83 and to the grooves 04- and are equally thei respective flange.

89 so as to correspond respectively to the .pairs of slots 83 and 84. These notches of piloting or indexing means for holding the drums against rotation during the period that a slide S is transferred therefrom into the propecting section of the machine,v and until such time as the slide has been returned and the period arrives for rotatively advancing a succeeding slide to the transfer station TS. A pin PR is adapted to thus engage in one of the notches 85 in the right-hand drum'D, Fig. 4, while a pin PL is adatped to thus engage with one of the notches 85 in the left-hand drum D in a manner fully described in the next section of this specification.

The terms slide" or "slides as employed in the specification denote a graphic film such as a picture bearing photographic sheet or the like F together with a frame or holder 81 with which it is assembled. Normally the film will be sandwiched between glass plates GL, Fig. 1, 2 and 10, to reinforce the same and insure its uniform disposal in the focal plane of the projector. One of the frames 6'! is shown in detail in Fig. 10. Preferably such'frames are made from a single piece of sheet metal and comprise two similar counterparts 88 connected by an integral intermediate portion 89 extending along their outer edges and having registering quadrilateral openings 18. A space is provided between the counterparts 88 so that the graphic-bearing sheet F and transparent plates GL may be slid to and from an assembled position therebetween. Cutway section-s 12, of which one appears in Fig. 10, may be provided in each of the counterparts 68 along an edge tllliereof to facilitate grasping of the finger tabs The inner edge of each slide S is formed substantially T-shaped in cross section, the two inner edges of the counterparts 88 being bent so that longitudinal edge portions 13 thereof are disposed in contiguous relation to jointly form the stem of said T-shaped section and are further bent to form opposed channel sections 74 which jointly form the crossbar of said T-shaped section. Tangs 13a on one of the edge portions 13 project through holes 13b in the other and are bent over to hold the frame assembled. These channel portions 14 are adapted to receive a coupling bar 15 having a latch tongue 18 turned substantially at right angles to the bar at one end as shown in Fig. 10. The opposite end of each'bar 15 has a head 15a together with shoulders 15b which are in abutment with their associated ends of channel portions 14 to prevent axial withdrawal of the bars. by pulling force applied to the tongues 1 a These tongues 18 are adapted to be coupled onto by the picker device PD to facilitate withdrawai and return of the slides from and to their respective drum holders scribed.

Disk-shaped side plates SP, Figs. 4, and 6, are secured to the outer sides of the housing walls 23 and 24 coaxially with the drums D, and these plates are of suflicient diameterthat outer edge portions are opposite the slide tongues l8 to prevent accidental inward displacement of the slides.

Notches N in the lower edges of the side plates 8? permit withdrawal fer stations TS. a i

Tns'Dazvs roa Carma Drums The slide holder drums which are freely roof the slides at the transtatabie upon their spindles 91 are rotatively adas will presently be de-' 85 serve as part vanced step by step to successively bring the slides S into registry with the transfer stations TS. Such advance of the drums is effected alternately inasmuch as slides are alternately withdrawn therefrom.

Driving force for advancing the slide carrier drums is derived through the vertical cam shaft 8| from which it is transmitted through a sectorshaped cam 88, a cam follower 8|, which is driven by the cam 88, and pins 82 and 83 secured on the cam follower in oppositely extending coaxial relation and which are adapted to be alternately inserted in the notches 85 of the drums D and moved circumferentially with respect to the drum axes for rotatively advancing the drums the desired amount. Said pins 82 and 83 serve as journals for bearings 88 and 85 at the upper ends of support links 88 and 81. The lower ends of said links 88 and 81 are provided with bearings 88 and 89 which are journalled on stub shafts 98 of which opposite end portions 9| and 92 are respectively anchored in and coaxial with configuration having a right camming face 93 (with reference to an observer standing at the front of the machine), a left camming face 94, a front camming face 95 and a rear eamming face 98. The generally sector shaped cam 88 has an arcuate camming surface 91 of long radius and an opposite arcuate cam surface 98 of short radius. Cam rise surfaces 99 and I88are between opposite ends of the arcuate surfaces 91 and 98. Cam points IM and I82 exist at the intersection of the long radiuscam-portion 91 and the rise portions 99 and I88. The distance between the opposed cam surfaces 93 and 99 is equal to that between the opposite cam surfaces 95 and 98; and the distance between any point on the short radius portion 98 of the cam 88 and the diametrically opposite point on the long radius cam portion 91 is also equal to distances between said opposed cam faces as 93 and 99 on the yoke-like follower. And the contour of the cam rise portions 99 and I88 is such that four peripheral parts of the cam will respectively and simultaneously contact some part of the cam follower faces 93, 94, 95 and 98, thus holding the cam follower against radial play with respect to the cam. During rotation of the cam shaft ll and of the cam 88 clockwise as indicated by the arrows in Figs. 5 and 8 the cam rise I88 will successively pass in registry with the can: follower faces 99, 95, 93 and 98.. With reference to Fig. 5, rotation of the cam 88 will first carry the face I88 along the cam follower face 98 for shifting the cam follower toward the left side of the machine (as viewed from the front) incident to sliding the bearings 88 and 89 on the lower ends of the links 88 and 81 along the stub shafts 98 and incident to withdrawing the pin 83 from its drum notch 85 and inserting the pin 82 into thedrum notch 85 in axial registry therewith. Itwill be seen that the pins 82 and 83 are projectable outwardly through openings I 83 and I8lin the housing side walls and openings I83a/and Na in the wall plates SP. Continued rotation of the cam 88 will carry the cam rise I88 along the-cam follower face 95 for displacing the cam follower rearwardly incident to pivoting the supporting links 88 and 81 upon the stub shafts 98 and also pivoting the bearings and 85 at the upper ends of said links upon the pins 82 and 83 while dispin 83 is disengaged from any of the notches 85 in the right-hand drum D, said drum will not be disturbed, but since the pin 82 is then engaged with one of the notches 65 in the left-hand drum D, this latter drum will be rotatively advanced by oneposition to advance a slide S into registry with its associated transfer station TS. Further rotation of the cam 80 carries the cam rise H along the cam follower face 93,-displacing the cam follower toward the right side of the machine (as viewed from the front) incident to sliding the bearings 88 and 89 in this same direction, along the stub shafts 90 and incident to withdrawing the pin 82 from its notch 65 and placing the pin 83 in one of the notches 85 in registry therewith. During the final quarter movement of a complete revolution of the cam at the cam rise it will pass face 95, carrying the pins 82 and 83 forwardly of the machinaithe pin 82 then having no effect since it is engaged with no notch 65 while the pin 83 causes rotative advancement of the righthand drum D by one position to advance a slide S into registry with its associated transfer station TS. It will be noted that the pin 82 causes rotationof the left-hand rearwardly of the machine whereas the pin 8-3 causes rotation of the right-hand drum Dwhile moving forwardly of the machine, and since the pins 82 and 83 are both above the rotational axes of these drums, they are rotatively advanced in opposite directions.

Pursuant to each revolution of the cam 88, starting from the position shown in Fig. 5, the pin 82' will be inserted in a notch 65 of its associated drum, moved backwardly with respect 'to the machine to cause rotative advancement of the drum, then the pin 82 will bewithdrawn from its notch while the pin 83 notch 85 of its associated drum and subsequently the pin 83 is moved forwardly with respect to the machine causing rotative advance of the righthand drum D. Thus one of the drums is first rotated in one direction and subsequently the other drum is rotated in the other direction pursuant to each complete rotation of the cam 80.

"It will be understood that each time onset the drums D is advanced a rotative step by its associated pin as 83 such pin is withdrawn from its notch 65, and, as explained hereinabove the pilot or holding pins PR and PL are then projected into respective of the notches 85 for holding the drums against rotation until such time as the slides are returned thereto and it is desired to advance the drums another step. These pilot pins PL and PR are upon opposite ends of a rod I supported for axial reciprocation .in bearings I05 and I01 in the housing side walls 2% and as near-the front wall-2i. The holes in these bearings 1.86 and ill! extend entirely through their walls so the pins PL and PR upon the ends of said rod are projectable outwardly through the walls. For instance, it will be seen in Fig. 5 that the pin PL is projected outwardly of the wall zs through the opening in the bearing Hi8 whereas in Fig '6 the pin PR will projected outwardly of the housing through theopening in the bearing I81. Reciprocatingzn'eans for the rod Hi5 consists of a lever I08 pivoted upon the shank of a headed fulcrum member I09 anchored upon abracket Ill proiectinginwardly from the hous ing sidewallila The drum D while moving is moved into a 1 back end of'the lever I08 along the cam follower flts'withm'a circumferential groove HI in the rod 188 whereas theyopposite end of this lever bifurcations Ill and III which are .upon

ward the housing opposite sides of a boss Ht oi the bearing 88 at the lower end of the supporting link 81 for the cam follower M. In Fig. 5 it will be seen that upon movement of the yoke like follower 8! toward the left side wall 23 of the housing incident to removing the pin 83 from its notch 65, and the movement ofthe bearing 89 and the boss Ht upon such bearing 89 with said follower, that said boss will cause the lever 108 to pivot clockwise for carrying its back end toward the right wall 21% of the housing and thus projecting the pilot pin PR into one of the notches 65 and thus holding the right drum D in the position to which it'had been advanced by the pin 83. When the cam follower 8i completes its movement toward the. left housing wall 23, further rotation of the cam M will cause the pin 82 to be moved rearwardly in its slot Hi3 for advancing the left drum D one step whereupon the parts will occupy the position illustrated in Fig; 6. Upon further rotation of the cam whereby the cam follower 84 is moved toward the housing wall 28 incident to withdrawing the pin 82 from its notch 65 the lever 18 will be pivoted counterclockwise, causing the rod N35 to be shifted toleft wall 23 and the pilot pin PL upon said rod N15 to be projected into one of the notches $5 on the left drum D for holding it in the desired position at which it has been rotated by the pin 82. Said lever it, since it is on a pivot point between the rod HOE-and the common axes of the pins 82 and as, causes said rod and said pins positions laterally of the housing H, that is, when the pin 83 is projected outwardly of the housing I wall as for being moved forwardly in the opening M14 and thus causing rotative advancement of the right-hand drum D, the pin PR will be retracted into the housing wall 24 and out of conditions are reversedwherefore the pin 82 is I outwardly of the housing wall -18 for projected disposal in one of the notches 65 of the left-. hand drum and imparting rotation to this drum. the pin PL will be retracted into the, housing wall 23' to permit this function of the pin 82;

'IiHE Spins Prensa MECHANISM The slide projecting section PS includes a frame like structure wherein there is a generally rec tangular web H5 partially filling the area enabraced between the housing bottom wall 25 and the supporting legs as and 21, saidweb H5 in this instance being cast integrally with thehousing wall 25 and said legs 28 and 27. A rectangular opening H6 is formed in the web H5 and there is attached to the back face of said 'web a metal, plate Ill which has a rectangular opening I of substantially the same size as the opening 8 and in axial registry therewith. Screws Hl'secure the plate M1 to the. web H5. Said web H5 and the plate ill are so shaped as to provide a channel in the'rebetween which is open at its opposite ends at the transfer stations TSJto prowlthdrawal of the sides 8. The lower edges 89 of to rest andslide along the I20 and-the opposite edges the channel portions 14 bottom of the channel or the head formed by 82 and 83 to occupy opposite the slides are adaptedregister with and are .r

edges of the latch-heads clined striking edges I48 and I49 are also formed engaged on the lugs I391- 138 is shown raised adapted to slide in opposed grooves I2I respectivelyin the web H5 and the plate I I1.

. Detent studs I22 and I23 are respectively carried upon leaf spring members I23x and I24 respectively at the top and bottom of the opening H6 in the web H5 and are pressed inwardly through holes I25 and I26 in the said web and by said springs for engagement in indentations or holes I21 and I28 in the counterpart 68 of the slidedisposed theretoward when the slide is disposed in registry with the projecting section. The springs I 23:: and I24, which may be of any I desired shape, are in this instance attached to the web II5 by machine screws I29 and I30: see Figs. 1, 2 and 4.

'The picker mechanism is for moving the slides into the space therefor between the web H5 and the plate I I1 and comprises a crosshead I3I which is reciprocal from right to left and from left to right between the upper portions of said web and said plate; Figs. 4, 8 and 9.

The crosshead I3I is made of pressed metal. It has a beaded section I32 for riding within a horizontal groove I33 in the plate I I1. A latch bar I34, Figs. 8 and 9, depends from the crosshead I3I. This bar is generally U-shaped, it having latch heads I35 and I36 at opposite of its ends and inwardlft urned lugs m and I38 which slidingly engage arcuate edge portions I39 and I40 at opposite ends of the crosshead. A loop spring I has its loop portion disposed within a notch I 42 in the lower edge of the having end hooks I43 and I44 engaged with the lower edge of the crosshead at opposite sides of seat portion I45 of the maintain the latch bar in a lower position which is established by lugs I39x and I40a: on the crosshead and disposed respectively at the lower termini of the arcuate edge portions I39 and I40 and downwardly upon which the lugs I31 and I38 are respectively engageable. Coupling notches I48 and I41 are formed in the lower I35 and I36 and inupon said latch heads,

The bead I32 riding in the groove I33 of the plate II1 prevents vertical displacement of the crosshead. However, the latch bar I34, while normally held in a lower position by the spring I4I with the lugs I31 and I38 at the lower ends of the arcuate edges I39 and I40 and downwardly and 0.1:, as shown in Fig. 9. is displaceable vertically bodily against the downward force of the spring I or is diilerentially displaceable, that is, either the latch head I35 or the latch head I36 may be raised independently of the other. In Fig. 8 the latch head while the latch head I35 remains in its lowermost position.

The inclined striking edges I48 and I49 on the latch heads I35 and I 36 coact with the spring "I4I for facilitating assembly of the slide-loaded drums D with the should a drunibe slid machine. For instance, onto its spindle 41 in such 1 -the.,inc1ined edge I49. ind thereby cam said latch head upwardly, the spring I4I then forcing said crosshead, said springlatch tongue may with the latch tongue 18 of a slide in its drum D, as illustrated in Fig. 9, the notch as I41 in such latch head provides adequate clearance that such be moved out of coupling relation with the latch head and that a succeeding latch tongue as 16 may be moved into coupling relation therewith pursuant to rotative advance of the drum D, and without disturbing the posi tion of the latch bar I34.

Driving force for the picker mechanism is received from the driving motor DM through the main cam shaft M and a cam I50 fixed nonrotatively thereto; see Figs. 1, 2 and '7. Said cam I50 has a short radius profile I5I and a diametrically opposite long radius profile I52 between the ends of which there are intermediate rise profiles I53 and I54. Points I55 and I56 occur at the intersection of the rise profile sections I53 and I54 with the long radius profile section I 52. A cam follower I5 1 in the shape of a yoke made from pressed metal .has an opening I58 surrounding the cam I50. This cam follower has upwardly turned fianges I59 and I60 at opposite edges of the opening I58 and which simultaneously bear in slidable engagement with oppositeperipheral portions of the cam I50. end of the cam follower is pivotally connected with a headed pivot post I63 screw threaded into a, boss I8I "formed integrally with a front part of the housing lower wall 25. The other end of ter portion of -a bolt I64 of which a threaded shank portion is passed through the cam follower and secured firmly thereto by a nut I65 turned tightly against the under face of the cam follower. The front end of the lever I62 is pivotally connected with a pivot pin I66 which is anchored in the bottom wall of the housing and which projects into an elongated opening I81 of the lever. At the back end of said lever I 62 there is a rectangular opening I68 through which spring extensions I69 and I 10 extendupwardly in opposed relation, said extensions being biased for gripping a section of a pin "I which is connected with the crosshead I3I. The extensions I69 and I10 are integral with a fiat metal piece I1Ia-riveted or otherwise connected to the under side of the lever I82.

Inasmuch as the cam I50 is connected for rotation with the cam shaft 4I, said cam will be caused to rot ate clockwise as viewed in-Fig. 7 with clockwise rotation of the cam as viewed in Figs. 5 and 6. One position of rest of the cam I50 and corresponding positions of rest of the cam follower I51 and of the lever I62 are shown in full lines in Fig. 7 whereas the other positions of rest of said cam follower and said lever are shown in dotted lines. I50 acts upon the opposed faces of the cam follower fianges I59 and I80 at points between the fixed pivot I63 and the swinging pivot I64, and since the latter pivot is associated with the lever I62 between the pivot I68 and the connecting pin "I to be moved by said lever I82, there is an amplification of the movement 01' the pin "I with respect to the eccentricity or throw of thecam I50. The elongated The back Since the cam lines in Fig. 1 thepicker by a pressed steel plate I18 cal edges of the shutter lever plate I88; see Figs. 1 and .portion of a the lever plate I88 which is I88, causing the love at the right side of the machine as shown in full device PD will also be at the right side of the machine since the .pin |1I is drivingly connected with the crosshead I3I of said picker device, and, it follows that -when the pin "I is at the chine said picker device will hand side.

Tm: Smrrrna Arm Diuvs Tnsiuiroi;

also be at the left- .shown in Fig. 1, when slides are at rest in the projection section. Prior to operation of the slide picker mechanism for shifting a slide to or from the projecting section the shutter plate I12 will be dropped into the position shown in Fig. 2 where it will remain untilthe new rest in the position to be projected.

left-hand side of the ma lever plate cars slide has come to I A guide slot for the slide plate I12 is provided a which is secured in spaced relation with and to the main/portion oi the front face of the plate I I1 by the aforesaid screws 8 and an additional screw I15. There isan opening I14 in the plate I18 in regi try with the webopening II8 to permit the projection of a light beam through the projecting sectionPS.

Other guide means for the shutter. plate I12 consists of vertical ribs I18 and I11 formed integrally with the housing side walls 24 and 23 and which have vertical grooves i18 and I19-which I88 and I8-I which project upwardly from the opposite vertiplate. Said vertical extensions I88 and I8I are, provided with forwardly directed vertical flanges I82 and JI88'in which there are pins I84 and I88 that project into elongated openings upwardly from the legs I88 of a fiat u-shaped 2. The lever plate I88 is fixed movement with a segmental gear I88 which is fixed-upon a cross shaft I8! having its two ends journalled .at bosses I84 and I85 Fig. 4. A second cross shown in dotted outline in shaft I86, arranged parallel with and generally above the shaft I8I, has its and sections journalied at I81 and I88 in housing side wall bosses I88 and288.,, A second segmental gear, 28I, is fixed upon the cross shaft I98 and meshes withthe segmental gear I88. A cam follower portion 282 on the hub of the gear 28I has a notch 283 late 284 which is shown in perspective in Fig. 3. 'This'cam 284 is for oscillating the gears 28I and I88 and aifixed to the-gear I88 to oscillate-beshown in Figs. 1 and 2. Be-

r plate tween the positions 'cause of the connection of the apertured ears I81 of the lever plate I89 with the pins I84 and I85 connected with the upward extensions at the side edges of the shutter plate I12, this osciliative movement-of the lever plate I88 causes vertical reciprocation of the shutter plate.

When either of the downwardly displaced profile sections 288-or 286 is disposed within the groove 283 of the cam follower portion 282 the segmental gear 28I will be rotated to the clockwise limit of its oscillative. movement shown in Fig. 1, causing the shutter plate I12 to heele- I88 in ears I81 turned generally" for oscillative I82 and I88 in housing side wall which receives a peripheral 'ture winding through hated H5 and Ennc'rsrc Dsrva AND CONTROL Cmcmrs Reference should now be had to Fig. 11 where an automatic electric circuit for controlling and supplying electric energy to the driving motor DM is shown diagrammatically. Both the timing motor TM and the driving motor DM are assumed, for the purpose of illustration, to be of the commutator type, that is,- of the type in which electric energy is supplied to the armabrushes which for the timing motor are designated 289 and 2I8 and which for the driving motor are designated 2 and 2I2. Separate field windings for the timing motor are designated 2I3 and 2I4 whereas separate field windings for the driving motor are desig- 2I8 and of which the latter is energizable to cause reverse rotation of the driving motor. Electric energy for the circuit may be obtained from a commercial supply through an outlet plug 2I1 from which a conductor 2I8 of one polarity leads to the movable contacts 2I8 and 228 of'switches 22I and'222 which are operated under control of the driving motor. A

' 222 is connected non-rotatively with the upper and the switch 22! open. Such reverse Ill) end of the vertical cam shaft 4|; see Figs. 1, 2,

15 and 16. An insulator block .224 upon which theswitches 22l and 222 are mounted is secured the housing so as to the cm 223. In Figs. 11 and 16 v shown with a notch or short radius profile portion 225 in registry with a rider 2280. on the contact springv member 228 which is of the leaf spring type switch-opening position, switch 222 to open. The tion 228 of said cam 223 is rider 221 on the switch contact which is also of the leaf spring type and to maintain this contact in the switch-closing position. Consequently the contact 228 and its mate 228 are openwhile the contact 2I8 and its mate 228 are closed. Should the cam 223 be rotated 188 the condition of the switches'22l and 222would be reversed, the switch 222 then being closed condieral sides of thus permitting the in registry with a tion is shown in Fig. 15.

The timing motor TM ing in some such manner as shown in Fig. 1. This motor, Fig. 12, has upon" its armature shaft 238 a worm pinion 23 I. which is effective through a speed reduction gear 232, a worm pinion 238 rotatable on a common shaft 284 with the gear 232, and a worm gear. 235 meshed with the pinion 233 for driving a driven shaft 238 and a cam 281 fixedto its upper'end. Said shaft 288 and the cam 231 are also shown in Figs. 11, 13 and 14. Figs. 11, 13 and 14 illustrate the association of timing switches 288 and 238m association'with the cam on opposite periphand biased toward thelong radius profile pormember 2I8 which is a constantly driven motor is mounted in the machine housgear train comprising a worm the electrical energy source.

231 for operation thereby. Said switches 238 and 239 which are of the leaf spring variety are supported upon an insulating block 248 which is mounted in any suitable manner as upon the the cam 231. The switch 239 has contacts 241 and 242 of which the-former is biased toward the switch-opening position whereby a rider 243 thereon constantly bears against the periphery of the cam. Switch 238 comprises contacts 244 tion 241 upon a cam lobe 248 and when this lobe switches will be open.

Referring once more to Fig. 11. attention is directed to a terminal block 250 having thereon a plurality of terminals respectively numbered for the terminals 251 and 255. In practice the bridging conductors 260 and 212 are connected between the prongs of a multi-prong plug (not shown), which prongs correspond respectively to and are insertable into physical assembly and electrical contact with their corresponding terminals of the block 250 when the plug is attached. Removal of the plug removes the bridging conductors 2611 and 212 to disable the timing motor portion of the control circuit. Also, in practice, the cable CA of the' manual control circuit has a multi-prong plug (not shown) upon its right end, Fig. 17, and the rongs of such plug, which are connected with respective conductors in their associated cable, are insertable into the terminals of the block 250 with which the conductors are to be electrically connected. However, the entire circuit in Fig. 11. together with its operation, will be described before describing the circuit in Fig. 17.

In the automatic setup, Fig. 11, the line 218 of one polarit is connected with the block terminal 255 through a conductor 259, and this terminal is connected with the terminal 251 through the removable plug conductor 260. The timing motor is connected in series, that is, with its field windings in series with the armature wherefore the circuit from said terminal 251 is continued through a conductor 261 through the timing motor winding 214, thence through the other winding 213,

' a conductor 262, brush 2| 11, the armature coil (not shown) connected with Said brush, brush 209, a conductor 263, the movable contact arm 264 of a variable resistance unit 265, conductor 266, a portion of a conductor 261, a main switch 268 which will be closed when the machineis started, and a conductor 269 back to the opposite polarity of Speed control of the timing motor is effected by adjusting the contact arm 264 along the resistance unit 265 of through the conductor 218 218 back to the energy source.

of the cam shaft 41 which the right endis connected through a fixed resistance unit 210a with a junction 211a of conductor portions connected respectively with the right end of the field winding 213 and with the armature brush 210. Inasmuch as the energization circuit for the timing motor TM remains established by conductor 268 connected between the terminals 251 and 255, the speed of this motor is regulatable by adjusting the switch arm 284 for varying the amount of theresistance unit 265 that is in series with the armature of the motor. By throwing the switch arm 264 crease the amount of resistance in series with the armature the motor speed is decreased.

Electric energy for the driving motor DM is ob tained through the conductor 281 which leads to the armature =brush 211, the circuit being continued through the armature to the brush 212 and thence through either of the and 216 to the terminal block. Winding 215 is connected with the'terminal 253 through a conductor 210 while the winding 216 is connected to the terminal 258 through a conductor 211. A resistance R is shunted across the motor armature to reduce its speed. Voltage of opposite polarity to that carried to the terminal 253 through the motor armature and winding 215 is applied to the terminal 252 at certain times, presently to be described, through the switches 221, 2.22, 238 and239. Therefore, the plug conductor 212 is used for connecting the terminal 253 with the terminal 252. The reverve field winding 216 is not energizable under control of the timing motor TM. As explained aibove electric energy of one polarity is obtained from the source and applied thereby upon each of the contacts 219 and 2211 in the drive motor switches 221 and 222. Contacts 228 and 229 of these switches 221 and 222 are respectively connected with contacts 242 and 244 of the timing motor switches 239 and 238 by means of conductors 215 and 216, and the contacts 241 and 245 of said switches 239 and '238 are con nected through a common conductor 211 with the terminal 252 on the terminal block 259.

In Fig. 11 the timing motor switches 238 and 239 and the driving motor switches 221 and 222 are illustrated in such condition that causes the the contact 228 to separate from the contact 228. Prior to the separation of the contacts 228 and 228 the driving motor was energized through a circuit including the conductor 261, the motor armature, the field coil 215, conductor 210 which is connected by the conductor 212' with the terminal 252, conductor 211, contact pair 241-242 of the timing motor switch 239, conductor 215, said contact pair 221i 228, and the conductor The driving motor cam 223, it will be recalled, is on the upper end of the vertical cam shaft 41 of the machine, Figs. 1, 2 and 4, and the short radius peripheral portion 225 of said cam is so arranged circumferentially with respect to the cam 150, Fi 7, and the shutter actuating cam-204, Figs. 1, 2 and 3, that the quiescent period of the drive motor incurred by said opening of the switch 222 occurs when said cam has actuated its associated cam follower 151 for stationing a new slide S in the projecting section of the machine and when said earn 204 has raised the shutter plate 112 to permit the projection of a projecting light clockwise to infield windings 215 beam thr u h said projecting section. Thus while thedriving motor is at rest the machine is otherwise conditioned for projecting the subject of a slide stationed in the machine projecting section. During this quiescent period of the driving motor DM the timing motor TM will be rotating the timing motor cam-231, say clockwise as indicated by the arrow in Fig. 11, whereby the long radius profile 241 will eventually come in registry with the switch 238 for closing the contacts 244 and 245. The driving motor switch 22I is then being held closed by the long radius profile 226 ofits associated cam. The speed of the timing motor is so regulated by the resistance unit 265 that the long radius profile 241 closes the switch 238 after the slide has been projected a predetermined length of time, and upon such closing of the switch 238'the driving motor DM will be energized for causing the machine to perform the operation of returning the projected slide to its carrier drum D and brin ing a new slide from the other drum into position for projection. This energization of the driving motor is effected by completion of a circuit including the conductor and field winding 2|5 of said motor, the conductor 216, the connected terminals 253 and 252, conductor 211, timing motor switch 238, conductor 216, driving motor switch HI, and the conductor 2|8 back to the energy source. After the new slide is in the projecting section of the machine and the machine is otherwise conditioned for the projection of such slide, the driving motor will have driven the driving motor cam 223 through 186 for bringing the short radius profile 225 into registry with the switch 22 I, permitting this switch to open and break the just described energization circuit for said motor and conditioning the same to again become quiescent during a succeeding slide projecting period. As

long as the plug 2|1 is connected with the energy source and the main switch 268 is closed the apparatus diagrammatically shown in Fig. 11 will continue to operate as aforesaid, the timing motor cam 23! operating continuously to periodically and alternately close the timing motor switches 238 and 233 to establish an energization circuit for the driving motor DM through one of the driving motor switches 22| or 222, causing the driving motor to commence operation and operate sufiiciently long to take the old slide from the machine projecting section and deposit a new slide therein and to then bring the short radius profile 225 into registry with the switch 22I or 222, which had been in series with the driving motor energization circuit, for opening said circuit and causing the motor to come to rest for a time determined by 'the speed with which the timing motor drives the timing motor cam 231.

Ormrron or rm: Mecnmn Timing motor control 233 which still remains closed. Consequentl all parts of the machine with the exception of the timing motor TM and the gear train associated therewith for driving the timing cam 231 are the contact arm 264 and 281, the armature that in which 2,875,706 at rest. A slide 8 is in the projecting section of the machine and is being projected upon a viewing screen or the like. The vertical cam shaft 4| which is at rest is in such position of rotation that the shutter actuating cam 264 has the downwardly disposed peripheral profile 265 within the cam follower section 262 of the seg- 7 mental gear 26I wherefore the mated segmental gear I8I and the plate lever I89 are rotated to their counter-clockwise position for maintaining the shutter plate I12 in its elevated position.

The cam 86 as viewed in Fig. 5 is in the position for .holdin the cam follower 8| toward the right side of the machine with the drum advancing pin 83 in one of the notches 65 of its associated slide holding drum. The point I62 of said cam 86 is in registry with the cam follower face 98 whereby the follower 8| is alsoat its foremost position so that the drum advancing pin 83 will have been moved forwardly in the side wall slot I64 and consequently the right-hand drum D will have been advanced for bringing a new slide S into coupling relation with the coupling head I36 on the picker mechanism as shown in Figs. 4 and 9. Since the cam follower 8| and hence the bearing 89 at the lower end of the link 81 associated with said cam follower are disposed toward the right side of the machine, the rib 4 on the bearing member 89 will be in position to hold the will be returned into the drum groove 83 of said left-hand drum D from which it had been previously transferred.

Further down on the cam shaft 4| and as shown in Fig.- '1 the cam I56 is in the full line position whereby the cam follower I51 and the lever I62 operated under control of said cam I56 are also in the full line, position for maintaining the slide picker mechanism at the right side of the machine as shown in Figs. 4 and 9.

After the slide at the projecting section of the machine has been projected for a predetermined time which is regulatable by changing the speed of the timing motor TM by regulating the position of the switcharm 264, Fig. 11, along the resistance unit 265, the timing motor cam 231 will bring thelong radius profile section 241 into the position for closing the timing motor switch 238. When this occurs a circuit will be established from the electric energy source through the conductor 269, control switch 268, conductor 261, brush 2 of the drive motor, the armature coil connected between said brush and the brush 2 I2, field winding 2I5, conductor 216, connected terminals 253 and 252, conductor 211, timing motor switch 238, conductor 216, driving motor switch 22I,.and the conductor -2I8 back to the other side of the electric supply source. Thus upon the closing of, the timing motor switch 238 the driving motor DM will be energized and will drive,

through the above described gear train, the vertical cam shaft M in the clockwise direction as During this energization of the first part of an operating cycle of the machine will be performed quickly. The driving motor will be permitted to run sufiiciently long to rotate the vertical cam shaft 4| and the various cams connected therewith through 186. The flrst'cam to perform its viewed from above. the driving motor pivot post I83 whereby the 'slide with which it is coupledv in the will then be in the dotted 7. It will be noted, however that rotation of 7 further movement to the of the cam shaft 4 function is the cam 204 positioned near the upper end of the cam shaft 4|. of its 180 rotation the cam follower portion 202 of the segmental gear 20I will be caused to ride upwardly onto the cam periphery 208 thereby causing said gear 20I to rotate counter-clockwise and the mated gear I8I and the plate lever I80 connected therewith to rotate clockwise for displacing the ears I81 on the two legs I88 of the lever plate downwardly. Thus the pins I84 and I85 disposed Within the openings I88 of said ears I81 are moved downwardly as well as the up'-,

Wardl extending parts I80 and m of the shutter -plate I12, said pins I84 and I85 in forwardly turned flanges extensions I80 and IBI. ter plate I12 will first be dispatch.

Early in said 180 profile I of the cam 80, Fig. 5, will begin to act against the camfollower face 94 of the cam follower 8| for throwing said cam follower toward the left side of the machine. Thus the pin 83 is withdrawn from its notch 65 in the right-hand drum D and the pin 82 is projected into a notch 85, of the left-hand drum D. Concurrently the being anchored I82 and I83 upon said Consequently the shutmoved downwardly with rib II 4 on the bearing 88 which moves axially with the pins 82 and 83 acts upon the lever I08 to cause its clockwise rotation and the projection thereby of the rod I toward the right side of the machine for projecting the pilot pin PR into one of the notches 65 whereby the right-hand drum D will be held against accidental rotation after withdrawal of the pin 83. This movement of the rod I05 toward the right side of the machine also withdraws the pilot pin PL from its associated notch 05 in the left-hand drum D so that this drum will be free for subsequent rotative advance by the pin 82. i

v Substantially concurrently of the pin 83 from the right-hand drum and the pin 82 into association with the left-hand drum the cam I50, Fig. 7, will carry its cam rise periphery I54 against-the cam follower flange I80 for pivoting the cam follower I51 clockwise about the lever I52 is pivoted counter-clockwise about the pivot pin IIiIiand to move the pin III and the slide picker device PD, of which said pin III isa part, toward the left side of the machine. This movement picker device causes the slide in the machine projecting section to be returned into it slot 83 in the left-hand drum D and effects tra sfer of the right-hand drum D into said machine projecting section. When the point I58 of the cam- I50 engages the cam follower flange I80 the slide picker device will have been transferred to the left side of the machine and the slide withdrawn from the right drum D will then be in the machine projecting section] The cam follower I51 and the lever I62 the cam I50 can continue withoutimpartin-g parts I51 and-I60 while sliding the long radius profile I52 along the flange I80.

After the slide picker device PD has 'been moved to the left side of the machine and during said continued rotation of the cam I50 while sliding the long radius profile I52 along the flange I80, pursuant to completion of the 180 rotation I, the shutter'actuating earn 204 will carry the I portion 208 into registry with the cam follower portion 202 of the segmental gear I so that During the first part with the movement Y of the cam shaft 4| the rise" motor switch 238, closing this switch and thus 82 rearwardly' whereby the position said gear, the gear I 9I, and the lever plate I88 will be rotated for again assuming their respective positions shown in rlg. 1. shutter plate I12 will be raised so the projecting beam will be etiectlve for pro ectmg tne/slide subject onto the viewing screen. Also during the latter portion of the 180 rotation or tnecam shaft M the rise profile I00 will be carried against the cam follower face 95 I01 projecting the pm the left-hand drum D is advanced one step for carrying the slide Just returned thereto out of coupling relation with the coupling neaa I38 or the Slide picker device PD and to bring a succeeding slide into coupling relation with said coupling head. The cam and the pins 83 and 82 will then be in the position illustrated in Fig. 6. Substantially at this time the short radius plofiie 225 on the motor cam. :28 arrives in registry with the motor switch 221 to cause the opening of this switch and the breaking of the motor energization circuit so that the driving motor comes to rest.

After the slide. has been projected for a predetermined tlme period of selected length the timing motor cam 48'! will again carry its long radius profile 241 into registry with tne timing completing a driving motor energization circult previously conditioned by the closing of the motor switch 222 by the long racuus pronle 228 of the motor driven cam 223 which was disposed in registry with said switch during the just described 180 rotation of the cam shaft II. This energization circuit for the driving motor includes the conductor 26], the driving motor armature coil (not shown) connected between the brushes ,2 and 2IZ, the driving motor field windings 2l5, conductor 210, the connected terminals 253 and 252, conductor Ell, switch 238, conductor 275, switch 222 and the conductor 2I8 back to the The driving motor thus energized will again be effective for driving the cam shaft 4| through 180 before the energization circuit for this motor is opened by the arrival of the short radius profile 225 in registry with the switch 222;

' During the initial part of this second 180 rotation of the cam shaft M the downwardly displaced profile portion 206 of the shutter actuating cam 204 will be withdrawn from registry with the cam follower section 202 of the segments ear 20I and the clockwisewhereby the mated lever plate I89 will be pivoted clockwise to the position shown in Fig. 2. Consequently the shutter plate I'I2 will be lowered into closing relation with the various light beam passing holes tIiIIi, I I8 and I74 in the machine projecting secgear I9I and the It will be recalled that the cam I80 was left in shown in'Fig. 6 at the end of the first 180 rotation of the cam shaft M. In the initial part of the present 180 rotation of said cam shaft the inclined profile I00 of said cam 80 will first be carried slidingly against the cam follower face 83 to cause movement the right whereby the pin 83 is pro d into one of the notches 85 in the right-hand drum D and withdrawing the pin 82 from its associated notch I85 in the left-hand drum D. Concurrently with this movement of the pins 82 and 83 to the right with the cam follower 8|, the lever I08 is Consequently the profile section 201 will be carried of the cam follower BI to drum during the finalpart of this 180 for causing its back end to shift the rod Hitoward the left side of the machine. The pin PR is thus withdrawn from the right-hand drum but the pin 83 is projected into one of the notches 65 of the drum to hold it against accidental rotation and preparatory to imparting rotation to said rotation of the cam shaft M. The pilot pin PL is proiected into one of the notches 65 of the left-hand drum to hold it against accidental rotation while the pin 82 is withdrawn from said drum.

After the shutter plate-cam 204 has rotated far enough to cause the lowering of the shutter plate I12, the profile rise lt l on the cam I50, Fig. 7, slides and acts upon the cam follower flange l59 for pivoting the cam follower lt'l counter-clockwise and for pivoting the lever I62 clockwise so that the parts It and IE2 begin their movement from their respective dotted line positions shown in Fig. '7 to the full line positions in that figure. When the point H58 on the cam ltt reaches the follower flange its the cam follower it'll and the lever I52 will reachthe full line positions in Fig. 7. During this clockwise pivotal movement of the lever lfiZ the slide picker device PD moved thereby will have been effective for returning the proiected slide to the right-hand drum D and to have transferred a new slide from the left-hand drum D, that is, the slide that was advanced into coupling relation with the coupling head it? of said slide picker device, into the machine projecting section.

\, Immediately upon the arrival of the new slide into the machine projecting section the incline on the shutter control cam 28 3, between the peripheral profile 2N and the downwardly displaced profile 2515, will be carried through the notch 2% in the cam follower portion 202 of the segmental gear till for pivoting this gear clockwise as viewed in Fig. l and to return said gear, the gear itl, the lever plate Hi9 and the shutter plate H2 controlled thereby to the positions shown in Fig. 1. With the shutter plate H2 thus raised, the slide just transferred into the projecting section of the machine will have its subject projected onto the viewing screen. As the cam shaft ii finishes this second 180 rotation the long radius profile on the cam Hit will slide idly along the cam follower flange I59 until finally arriving at the full line position shown in Fig. '7. Also during such final rotation of the cam shaft M the rise profile ml] of the cam 88, Fig. 6, will be carried against the cam follower face 96 whereby said cam follower is moved forwardly in the machine as is the pin 83 for advancing the right-hand drum one step whereby the slide S just returned thereto by the movement of the slide'picker device PD to the right side of the machine will be moved out of coupling relation with the coupling head its and a new slide is moved into coupling relation with said coupling headpr'eparatory to being transferred into the machine upon the starting ora new operating cycle.

'At this time the parts will all have been retumed to their respectivepositions shown in Figs.

1, 4, 5, 7, 9, 11, 14 and 16. The short radius profile 225 of the driving motor cam 223 will have arrived in registry with the switch 222, causing this switch to open and the energization circuit for the driving motor to have been broken. Subsequent operating cycles. of the machine will oc- Manual control Inasmuch as the timing motor switches 238 and 239, Fig. 11, are operable to control energization of the driving motor circuit simply by being alternately closed under control of the timin motor cam 231, it will be apparent that switch means corresponding to the switches 238 and 239 may be actuated manually for controlling energizatlon of the driving motor circuit to cause operation of the driving motor at desired times which may be intervened by rest periods of desired duration. When the driving motor circuit is controlled by the timing motor cam 231 which rotates at selectable constant speeds the rest pe; riods between driving motor circuit energizations will, of course, be of equal length.

Manual control of the driving motor energizetion circuit is effected by employing the conductors and diagrammatic switch structure shown in Fig. 1'7 instead of the switches 238 and 239 in Fig. ll, and the timing motor TM. The first step in the change over from the automatic control to the manual control is to disconnect the bridging conductors 2th and Eli from their associated terminals on the receptacle or terminal block 250, and, as explained above. this disconnection of said conductors from their respective terminal block terminals may be expedited by the use of a pronged plug (not shown) having prongs respectively corresponding to the terminals 25l-255 and 2ii2tt between which the'conduciers 2th and Eli are actually connected and which prongs are readily insertable and withdrawable fromrcspective physical and electrical conductive association with the terminals Edi-Q55 and 252-253. Breaking the electrical connection between the terminals Edi-Q55 deenergizes the timing motor, whereas breaking the tween the terminals 252-253 dead ends the contacts 2 3i and 2% of the timing motor switches 239 and 238 to render these switches inefiective.

Following the disconnection of the bridging conductors 2th and 272 the switch controlling apparatus of Fig. l? is connected with the terminal block by having the cable conductors 216b,

Z'ltb, Ella and Ella thereof respectively connected with the terminals 256, 257, 253 and 258 as indicated by the dot-dash lines extending be- After the conductors 26d and 212 have been disconnected from their terminals on the block 250 and theconductors in the cable CA have been connected with their terminals on said block, the manually operable switch contact 211a: will be manipulatable to close and open driving motor energization circuits cooperably with the driving motor control switches 22I and 222 in the same manner that the timing motor switches 238 and 239 were manipulatable cooperably with the driving motor switches. Preferably the switch comprising the contact 211a: is of the Push-Push" type. One push upon a control button of such a switch would cause the contact 2172: to move away from its electrical connection with the contact electrical connection bei 242a to the dotted line trical connection with ceeding push upon the the contact 2113: to position. That is, the contact 2113: would shift between the full line and dotted line positions and each time the PushPush switch button is pressed the contact 211:): will move to the other of the contacts 242a and 244a than that with which it happens to be associated. A reversing contact 211z,is likewise shiftable between electrical connection with a contact 211) and a contact 2111' under control of a second button on the Push-Push switch. The contacts 211:: and 211;: are connected in series through a conductor position where it is in electhe contact 244a and a succontrol button would cause 211p, and as will be presently explained, when the contact 211:1: is moved into electrical connection with one of the contacts 242a or 244a to energize the driving motor, the motor will run connected with the contact 271r it will rotate reversely.

Assuming the switch contacts 211:: and 211a to be in the full line positions illustrated in Fig. [1, the driving motor DM will be at rest. This is because the driving motor cam 223 has been rotated to the position shown in Fig. 11 for open-' ing the switch 222. Prior to such opening of the switch 222 the motor upon movement of the contact 211:: to the full line position was energized through a circuit including the conductor 289, main switch 268, conductor 261; the driving mointo the cable, CA, switch contact 211} and 2112, conductor 2111 contacts 211a and 242a, cable conductor 215b, terminal 251, conductor 215, driving motor switch 222 and conductor 2|B back to the energy source. When the driving motor had operated long enough to return the projected ing the driving motor energization circuit. long as the switch contact 211a: allowed to remain connected with the contact 242a the driving motor will remain at rest while the slide in the projecting section of the machine is being projected. When the slide has been projected i for a period which may be determined by the M5, conductor 210, terminal 253, cable conductor 211a, switch contacts 211i and 2112, conductor 211 contacts 211:: and 244a, cable conductor 216b, terminal 256, conductor 216, driving motor switch 22I and the conductor 2! back to the side of the energy source of opposite polarity. Upon the establishment of this energizing circuit for the driving motor it willv rotate for driving the machine cam shaft 4| and the driving motor cam 223 through 180 for effecting the hereinabove described opbe returned to the full line ,slide picker device PD, which erations of the machine parts for transferring the projected slide from the machine projecting section into its respective drum and for transferring a new slide from the other drum into the projecting section and otherwise conditioning the machine for projecting the new slide. Upon the completion of this 180 rotation of the driving motor cam 223 the long radius profile 226 of said cam will cause the switch 222 to be closed and the switch 22! or the just described energization circuit to be opened and thus cause the driving motor to come to rest. Alternate energization'of the above described energization circuits for the driving motor is obtainable to cause the machine to run through successive operating cycles simply by alternately throwing the switch contact 211x first to one of the two contacts 242a and 244a and then to the other Sometimes it will be desirable t run the driving motor in the reverse direction for reversing the operation of the machine parts whereby the slide holding drums D will be advanced in the reverse direction and the slides will be displaced in the reverse order to that taking place in the operations of the machine thus far described. It will be observed in Figs.3, 5 and 7 that the actuating cams 204, and I5!) driven by the main cam shaft 4| are symmetrical so that they may be driven in either direction for causing operation of their respectively controlled parts coordinately with the parts controlled by each of the other cams. The cam 80 has symmetrically arranged cam rise profiles I00 and 99 either of which is slidable along the faces 93, 94, and 96 of the cam follower 8| for imparting movement to this cam follower. In the description hereinabove of the operation of the cam 80 and its follower 8| the cam was described as rotating clockwise, Fig. 5, to cause the rise I00 to successively engage the cam faces as 93 of the follower whereby said follower was given a clockwise revolving movement with respect to the axis of rotation of the cam 80. However, as thecam 80 is rotated in the counter-clockwise rotation, the cam rise profile 99 thereon will operate cooperably with the faces as 93 of the follower 8| in successive but reverse order of association whereby said follower will revolve counter-olockwise with respect to the cam axis. This counterclockwise revolving of the cam follower will cause the pin 83 to advance the drum it is associatable in the opposite direction to which it Was advanced by this pin 83 when the follower 8| was revolved clockwise, and, the pin 82 upon the follower will also be manipulated for rotating its associated drum D in the opposite direction heretofore described.

In the operation of the cam I50 in Fig. 7, when the cam is rotated counter-clockwise instead of clockwise by reverse rotation of the driving motor DM, the rise profile I53 will effect the oscillative movement of the follower I51 instead of the rise profile I54, to coordinate the movement of the is moved under control'of the follower I51, coordinately with the advance of the drums D in their reverse direction under the influence of the reversely driven cam follower 8|.

Reverse rotation of the driving motor DM is obtainable by throwing the switch contact 2112 from the full line position shown in Fig. 17 to the dotted line position in conducting relation with the contact 2111-. This movement of the contact 2111:: against the contact 2111' is eifective for connecting the reverse field winding 2 I 6, Fig. 11, in series with the movable switch contact 211:, Fig. 17, the

D with which a the field winding circuit portion establishing the series relation of 2H5 with the movable contact 211:: including the conductor 2111/, said contact 2112, contact 2111', cable conductor 2] la, terminal 258 and the conductor 21L Inasmuch as throwing the switch 2112 against the contact 2111' merely substitutes the reverse field winding 2 it in the motor energization circuit in lieu of the forward field winding H5, and inasmuch as the driving motor cam 223 is in the position for causing the switch 222 to be opened and the switch contact 2113: is disengaged from the contact Mia, the placing of the movable contact 2112 against the contact 211r will not effect energization of the motor energizing circuit. Energization of the driving motor circuit will not occur, as when the contact 2112 was against the contact 211i,-unti1 the Push-Push switch control is manipulated for throwing the contact M le. When this occurs the energization of the driving motor for reverse rotation will be through the circuit including the conductor 269, main switch 268, conductor 261, the driving motor armature, reverse field winding 2l5, conductor 21!, terminal 2%, cable conductor 21m, contacts 2111 and 2112, conductor Z'l'ly, contacts 211a: and Wide, cable conductor 21%, terminal 253, conductor 2W, switch 22! and the conductor 2H3 back to the energy source. The machine is then driven by the reversely rotating motor to replace into the projecting section of the machine a previously shown slide which it is desired to again examine. As when the forward field winding Bid is connected for energization by the throwing of the switch contact 211:0, when the contact 2112 is against the contact 2111', the driving motor cam 223 will rotate 2111: against the contact 180 before opening the switch 2M whereupon the motor will stop. Subsequent energizations of the driving motor are effected by alternately moving the contact 211a: between the fixed contacts 26% and 262a to cause the machine to back up for the showing of as many slides in reverse order as is desired. I a

In addition to-being capable of continuous and automatic operation, the moving parts of the machine in efiecting such operation are inherently quiet in the performance of their functions, and,- in this respect the principal parts are quiescent during slide projection periods when the absence of noise is particularly desirable.

Another advantage of the machine concerns the efficient use of two slide holders whereby Y a single slide picker device is operable to transfer the slides from each slide holder and back again. Moreover, the alternate transfer of slides from the holders and concurrent return of the projected slides to their respective holders re-.

sults in a large capacity machine in which no adjustment isnecessary before starting the projection of the slides on the second holder. Also, after the series of slides has been run through they will be in their same relative positions in the holders as at the start of the exhibition, so the machine can be left running indefinitely to project the series over and over again.

Another important advantage of the apparatus is its adaptability to be employed as a fully automatic machine under control of the timing motor or by the manual control, and the ease with which th change can be made from the automatic to the manual control. It should also be noted that when they apparatus is operating under the manual control that the projecting period may be varied from an instantaneous period to one of indefinite length. By throwing the manually controlled switch contact 2113: to the other of the two contacts 242a or 244a immediately upon the machine performing the operation of withdrawing a slide from a slide projecting section and inserting a new slide into that section, the driving motor DM can be caused to drive the slide holder drums D forwardly or, backwardly, depending upon the position of the switch contact 2112, for quickly bringing into the projecting section of, the machine a slide which may be disposed some distance circumferentially of its drum from the slide transfer station associated with that drum.

While we have thus described our invention, we do not wish to be limited to the precise details described, as changes may be readily made without departing from the spirit of our invention', but having thus described our invention, we claim as new and desire to secure by Letters Patent the following:

i. In a slide projector machine wherein there are parts driven through a cycle pursuant to one portion of which a siide istransferred from a slide transfer position at a slide holder into a projecting sectionof the machine and a light beam transmitting the slide subject is thereafter projected from the machine, and pur suant to a second portion of which cycle the slide is returned to the holder and the latter is then operated to dispose a succeeding slide in said transfer station preparatory toa repetition of said cycle;' the combination of an electric driving motor operable to drive said parts, an electric timing motor energized independently of said driving motor, an electric circuit comprising a plurality of circuit portions in control of the driving motor and of which either is conditioned by closing to cause operation of the driving motor, each of said circuit portions including a driving motor switch and each of said portions being open when either of its switches is open and being closed when both of its switches are closed, timing motor switch actuating means operable according to the speed of said timing motor to cause alternate closing of the timing motor switches, and driving motor switch actuating means operable coordinately with said motor to cause the opening of one of the driving motor switches upon the completion of one of said cycle portions while causing the closing of the other; and to cause the opening of said other driving motor switch upon the completion of the second cycle portion while causing the closing ofk'said one driving motor switch, whereby upon the completion of each of said cycle portions the respective circuit portion for the driving motor will be opened to stop the motor and the other circuit portion will be conditioned for closing by the closing of itsrespective timing motor switch at a time determined by the speed of the timing motor.

2. In a slide projector machine wherein there are parts driven through a cycle pursuant to one portion of which a slide .is transferred from. a slide transfer position at a slideholder into a projecting section of the machine and a light beam transmitting the slide subject is thereafter projected from the machine, and pursuant to a second portion of which cycle the slide is returned to the holder and the latter (is then operated to dispose a succeeding slide in said motor switch and a timingtrio timing motor energized independently of said driving motor, and an electric circuit including switch means manipulatable to condition said circuit with respect to its energization for causing energization of the driving motor so said motor is effective for driving said machine parts and being also manipulatable to terminate such condition, said switch means being manipulatable under control of the driving motor to terminate such circuit condition upon the completion of each of said cycle portions and thus cause the driving motor to stop, and 'said switch means being manipulatable under control of said timing motor to recondition said circuit at a predetermined time after such stopping of the driving motor to cause v execution of the succeeding cycle portion,

3. In a machine of the class described including an axial projecting beam'section into which slides are transferable from transfer stations at opposite of its sides, a slide picker device reciprocal between said transfer stations transversely of the projecting section and operable in each reciprocal sweep to transfer into the projecting section a slide from the transfer station of departure and to return to the station of destination a slide from the.projecting section, a rotatable drive member disposed between said stations opposite a third side of the projecting section, said drive member being rotatable about an axis generally perpendicular to the projecting section axis and having a drive imparting portion displaced orbitally about such axis during rotation of the member, and means drivingly connecting said slide picker device with said drive imparting portion of the drive member in a manner that imparts to said device a reciprocal displacement constituting an amplification of the throw of such portion, comprising a follower disposed on the side of said projecting section with said drive member, said follower having a first portion spaced in one direction from said drive member axially of the projecting section and displaceable laterally of said section in the direction of reciprocation of the picker device, a second portion spaced in the opposite direction from the drive member and pivotally'mounted to facilitate said displacement of the first portion, and an intermediate portion of the follower being operably associated with the orbitally movable drive member portion for receivingdriving force therefrom to cause such displacement of the first follower portion, and a lever member on the side of'the projecting section with the follower, said lever extending axially of the projecting section and having a first portion between the first and second portions of the follower that is drivingly connected with the picker device therewith transverselly of the projecting section, said lever having a second portion spaced oppositely to the first portion thereof axially of the projecting section with respect to said laterally displaceable portion of the follower and that is pivotally mounted to facilitate such transverse movement of the first lever portion, and said lever having an intermediate portion pivotally connected with the laterally movable portion of the follower whereby the latter cooperates with the pivotally mounted second portion of the lever in imparting such transverse movement to the first lever portion for driving the picker device.

4. In a machine of the class described includ ing an axial projecting beam section into which and movable reciprocally slides are transferable from transfer stations at opposite of its sides, slide holders at said sides of the projecting section and rotatable about a substantially common axis normal to and spaced laterally from a third side of said projecting section, said holders each having means for releasably holding thereon a plurality of slides distributed circumferentially thereabout at such radial distance as to be carried successively into registry with said transfer stations pursuant to rotation of the carriers, cam-driven means between said slide holders at a position spaced from said third side of the projecting section in the same direction as the holder axis and operable for alternately rotatively advancing said holders to dispose the slides thereon in registry with the transfer stations as aforesaid, a cam shaft extending perpendicularly to the projecting section upon said third side thereof between said holders, a cam on and driven by said shaft for operably driving said cam-driven means, a cam-driven slide picker device reciprocal between said transfer stations transversely of the projecting section and operable in each reciprocal sweep to transfer into the projecting section aslide from the transfer station of departure and to return to the transfer station of destination a slide from the projecting section, and a second cam on and rotatable-with said shaft for operably driving said picker device in such timed relation with the drums. that each slide is transferred into the projecting section and returned to its transfer station prior to 'a succeeding advance of its drum for advancing a new slide to such station.

5. In a machine of the class described including an axial projecting beam section into which slides are transferable from stations at opposite sides of said section to have their subject projected by a beam in said section, a power shaft between said stations opposite a third side of said section and with its axis substantially normal to the projecting section axis, means operated from said shaft for transferring slides from said stations into the projecting section and back to said stations, a shutter member reciprocal transversely of the projecting section to and from a position of registration therewith along a path of movement generally parallel with the power shaft, a pivoted member pivotally mounted for oscillative movement about an axis on said third side of the projecting section that is spaced axiall of said projecting section from the power shaft and that is substantially perpendicular to the axis of said shaft, arms oscillatable with and projecting from said pivoted member respectively at said opposite sides of the projecting section, said arms being operably connected with opposite edges of the shutter member to move the same into registry with the projecting section when the pivoted member is pivoted in one direction and to move said shutter member out of such registry when pivoted in the opposite direction, and drive means on and rotatable with said power shaft operably connected with said pivoted member for oscillating the same during rotation of the power shaft, and said drive means being further operable to oscillate said pivoted member for operating the shutter in such timed relation with the slide transfer means that the shutter is in registry with the projecting section during movement of a slide into or from the projecting section and is out of such registry while a slide is at rest in the projecting section.

6. In a machine of the class described including an axial projecting beam ,qnr-Hnn in v uted circumferentially thereabout at suchradialdistance as to be carried successively into registry with said transfer stations pursuant to rotation of the carriers, a rotatable power shaft extending perpendicularly to the projecting section upon said third side thereof between said holders. holder driving means between said holders on the third side of said projecting section and operably connected with and driven by said shaft for alternately rotatively advancing said holders to dis- ,pose the slides thereon in registry with the transfer stations as aforesaid, a slide picker device on said third side of the projecting section and drivingly connected with said shaft for-reciprocation gularly about and facing an axis generally normal to said orbital path and a cam mounted for rotation on said axis and operable on said-cam engageable surfaces to effect movement of said advancing member in said orbital path.

10. In a slide projector machine including a projection section in which slides are transfer-.

able from transfer stations at opposite of itssides, the combination of slide'holders at respective of said sides and'advanceable in corresponding paths to bring slides carried in sequence thereon to said transfer stations, and means for intermittently advancing said slide holders comprising an advancing member extending between saidslide holders and mounted'for movement in a rectangular orbital path disposed to provide reciprocation of said advancing member both lineally and transversely of said slide holder paths and provided at the opposite ends thereof thereby between said transfer stations and operable in each reciprocal sweep to transfer into the projecting section a slide from the station of departure and to return a slide from the projecting station to the transfer station of destination, a shutter member reciprocal transversely of the projecting section to and from a position of registration therewith along a path generally parallel with the power shaft and operably connected with said power shaft to be driven thereby in effecting said reciprocal movement, and the connections of said holder driving means, said slide picker device and said shutter member with the' power shaft'being coordinately operable in such relation that each slide transferred by the picker device into the projecting section is returned to its transfer station prior to a succeeding advance of its drum and that the shutter is in registry with the projection section during movement of the slides in or out of the projecting section and with oppositely disposed advancing formations alternately engageable with cooperating series of advancing formations respectively on said slide holders by reciprocation of said advancing member transversely of said slide holder paths and provided intermediately thereof with two pairs of parallel cam engageable surfaces arranged angularly about and facing an axis generally normal to saidorbital path and a cam mounted for rotation on said axis and operable on said cam engageable surfaces to effect movement of said advancing member in said orbital path, a holder pilot extending between said slide holders and mounted for reciprocation transversely of said slide holder paths and provided at the opposite ends thereof with oppositely disposed pilot foris out of such registry while a slide is at rest in the projecting section.

'7. In a slide projector machine, the combination as recited in claim 1 and further characterized in that manually adjustable speed conprovided.

8. In a slide projector machine, the combination as recited in claim 2 and further characterized in that a manually adjustable variable resistance connected in circuit with said timing- V sponding paths to bring slides carried in sequence thereon to said transfer stations, and means for intermittently advancing said slide holders comprising an advancing member extending between said slide holders and mounted for movement in a rectangular orbital path disposed to provide reciprocation of said advancing member both lineally and transversely of said slide holder paths and provided, at the opposite ends thereof with oppositely disposed advancing formations alternately engageable with cooperating series of advancing formations respectively on said slide holders by reciprocation of said advancing member transversely of said slide holder paths and provided intermediately thereof with two pairs of parallel cam engageable surfaces arranged m trolling means operable on said timing motor is j 'of advancing formations respectively on said slide holders, and a motion reversing operative connection between said advancing member and holder pilot and operative to reciprocate said holder pilot transversely of said slide holder paths in reverse relation with reciprocation of said advancing member transversely of said slide holder paths to engage said holder pilot with said slide holders in alternation with engagement of said advancing member therewith.

11. Ina slide projector machine including a projection section in which slides are transferable from transfer stations at opposite of its sides, the combination of substantially coaxial slide holders at respective of said sides and rotatable about their axis to bring slides carried in sequence angularly thereon to said transfer stations, and means for intermittently advancing said slide holders comprising an advancing member-extending between said slide holders and mounted for angular movement substantially about and for movement substantially parallel to said axis and thus mounted for movement in a rectangular orbital path providing reciprocation of said' advancing member both lineally and transversely of the rotational movement of said slide holders and provided at the opposite ends thereof with oppositely disposed advancing formatlons alternately engageable with cooperating series of advancing formations respectively on said slide holders by reciprocation of said advancing member transversely of said slide holder movement and provided intermediately thereof with two pairsof parallel cam engageable surfaces arranged angularly about and facing an axis, generally normal to said orbital path and 

